Hydraulic transmission



. April 9,1940.

J. B. DAvls 2,196,522 HYDRAULIC TRANsu'IssIoN Filed nay 8,'1959 3 Sheets-Sheet 2 A9319, 1940' J. Bf DAvls 2,196,522

HYDRAULIC TRANSMISSION Filed nay a, ,193s s sheets-spe s ly f@ 5tlg 7' v Patented Apr. 9, 1940 UNITED STATES HYDRAULIC TRANSMISSION John BfDavis, Dallas, Tex., assignor to Hydraulic Production Corporation,. Dallas, Tex.

Application May 8, 1939, Serial No. 272,488

1 Claim.

This invention relates to new and useful improvements in pumping units of the balanced type particularly adapted to the pumping of oil wells or other similar heavy pumping operations.

One object of this invention is to provide a principle or system of balanced pumping operation which system may pump one or more wells from a central plant wherein the speed of 'operation of each well may be individually controlled. Another object of the invention is to provide a balanced pumping unit which may be controlled remotely.

Still another object of the invention is to provide a balanced pumping unit wherein all means l5 for counterbalancing the Weight of sucker rods,

or other similar units, are completely eliminated.

Another object of this invention is to provide a hydraulically controlled balancing means which will overcome all rod loads to decrease wear on the gear box and gear equipment thereby providing a thoroughly satisfactory harmonic motion.

Another object of the invention is to provide an automatic balanced pumping unit to offset any rod load regardless of depth or load to completely eliminate any means for counterbalancing 'weighted cranks or beam weights.

Another object of the invention is to provide automatic means for overcoming rod loads whereby the only weight to be handled by the pumping equipment is that Vof the live uid loads which occur only on units.

Another object of the invention is to provide l a simplied universal movement between the sucker rods of an oil well pump, the beam actuating mechanism and the improved automatic hydraulic balancing means whereby only a true vertical movement of said sucker rods is had in the pumping operation.

Still another object of the invention is to provide an extremely simplified connection means between the automatic hydraulic balancing means as well .as to eliminate most of the pumping equipment now required to operate a producing well.

A construction vvention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in f which an example of theinvention is shown, and

wherein: l

Figure 1 is a view partly in elevation and partly in plan to illustrate one form of pumping means the up strokeof said pumping,

designed to carry out the inas well as connections from a number of wells to the master cylinder.

Figure 2 is a view l in elevation showing details ofthe and automatic control valve.

Figure 3 is a view partly in elevation and partly in section of the master cylinder.

Figure 4 is a horizontal cross-sectional view taken on the line 4-4 of Figure 1.

Figure 5 is a detail sectional view taken on the l0 line 5-5 of Figure 4.

Figure 6 is a view of a slightly modied form of the invention.

Figure rI is a detailed elevation of the safety or blow-oli valve. 1 i Figure 8 is an enlarged vertical sectional View of the vent.

In the drawings the numeral I0 designates the usual Christmas tree mounted on the upper end of a'well casing Il. The usual suckerrods l2 are 20 connected to the reciprocating means either as shown in Figure 6 or the conventional walking beam, not shown.` f

The present invention comprises primarily a hydraulic plunger 20 which plunger is slidably mounted in a cylinder 2| whereby the plunger may be reciprocated by hydraulic means. A suitable receptacle 22 is mounted on the upper end of the plunger 20, said receptacle being capable of retaining any substance suicient to carry outthe purpose of the present invention. This receptacle is iilled with iron or lead weights of such combined weight as to counter-balance the rod load in a well tov which its operating cylinder 2| is connected.

A trip switch 30, is provided as shown in Figure 2. This switch' serves no valve function in its application as in Figure 1, but is effective, as will be later explained, as a means for electricallyoperating a valve for controlling the flow of iiuid in the system. A fluid passage through the switch housing 3U is assured at all times regardless of the position of the arm 30a.

By observing Figure 1 it will be seen that channel bars 3l are provided (Fig. 4) which bars serve as a guideforpff center rollers 36. A hydraulic plunger 31 within a cylinder 38 is provided to acv complish a reciprocable movement of the sucker rods I2 as will be hereinafter described in detail. A member 32 is provided with rollers 36 at its 50 upper and lower ends which rollers, as has been stated, are confined within the chanel bars 3l. The sucker rods l2 of the well il are universally secured to the member.32 as will hereinafter be explained, while the opposite end of the member partly in section and partly trip switch 321s so arranged as to actuate the trip switch as may clearly be seen by observing Figure 1.

To clarify the operation of the mechanism thus unit A and in this series a pump 48 is employed. This pump is /suitably connected to the master 4 balancing unit .A by means 4| as well as being connected to a pressure line 42. The pressure line 42 is connected directly to the cylinder 38 containing the plunger 31 by means 43. 'I'he trip switch 30 as well as a throttle valve 44 are mounted in the means 43 intermediate the pressure line 42 and cylinder 38. An automatically controlled valve 45 is also mounted in the connecting means 43 which valve 45 contains a by-pass means, which will hereinafter be explained.

As the member 32 is forced upwardly by the combined fluid pressure of the pump 48 and balancing means A in cooperation with the plunger 31, a rod 45 will be actuated. This rod 45 is slidably connected to the member 32 at its upper end while it is suitably connected to the trip switch 30 at its lower end. Thus, when the sucker rod has reached' its maximum up-stroke the trip switch, due to connections therewith to the valve 45, will relieve the now oi hydraulic pressure through valve 45 to allow the member 32l to travel downwardly, which member, as has been explained, is guided in its downward course by means oi.V channel bars 3| and rollers 35. At such time as the member 32 reaches its maximum downward point of travel the member will again be actuated to operate the trip to electrically change the position of the valve 45 to again exert pressure into the cylinder 38 to raise the plunger 31. l

In Figure 1 connecting units B and C are shown for purposes of illustration. T'he portions 41 and 48 of units B and C, respectively, may be connected to any suitable actuating well mechanisms (not shown).

By observing Figure 3 an elevation-of the unit A may be seen. As has been explained the receptacle 22 is mounted upon a plunger 2li, which plunger is conned within the cylinder 2| which cylinder contains a predetermined amount of hydraulic iluid (not shown). The weight of the substance within the receptacle 22 is sulcient to compress the iluid to such an extent that said iiuid will exert a pressure only a fewpounds less than that pressure exerted upon the pumping unit by the rod load. I'Ihus, for example, if the rod load be three thousand pounds the pressure exerted by the balancing unit may be two thousand seven hundred and fty pounds. With this amount or percentage of balancing it will be necessary for the pump 40 to actually prounit will reduce actual exertion of the pumping unit employed to one sixth of that normally required.

Byobserving Flgure3 it will be seen that the receptacle 22 of the unit A must be permanently r suspended, that is, the receptacle 22 can at no time be lowered to such a degree that said receptacle may rest on any portion of the cylinder mounting D. If this were to occur the weight of the substance within the receptacle 22 would bear against said mounting D and, therefore, could not exert its weight upon the hydraulic iiuid within the cylinder 2|.

To overcome any possibility of this occurring a safety switch 50 is provided. This switch is so arranged as to close the contact to an auxiliary pump 5| in the event that the receptacle 22 is lowered to the horizontal plane of said switch 50. At such time as the member 22 is lowered to such a'degree as to strike a pivoted contact arm 52 of the switch 50, a direct circuit` will be closed to the auxiliary pump. This pump is connected to a hydraulic iluid reservoir 53 whereby when. at such time as a circuit is closed to the pump, additional iiuid will be introduced, by the pump, to the cylinder 2| to raise the plunger to a suiilcient height whereby a permanent suspension of the substance within the receptacle 22 is had.

By observing Figure 2, details of the trip switch 30 and automatic valve 45 may clearly be seen. Figure 2 discloses a completed circuit between the trip valve 35 and automatic valve 45- through switch 43. 'Ihe valve 45 comprises a housing 50 having a plunger 5| slidably mounted therein. Sliding movement of this plunger is had through the medium of a torque motor 52 which motor has a circular gear 53 mounted on the drive shaft 53 thereof. The gear 53 is arranged to mesh with'a gear rack 54, which gear rack is suitably connected to the slidable plunger 5|. To eliminate any possibility of vacuum or compression within the member 58 above and below the slidable plunger 5|, vent valves 95 are providedin the upper and lower ends of the member 58. By observing Figure 8 the enlarged details of the valve may be clearly seen. 'I'he valve comprises a housing $5 closed at one end by a ball valve 91 and by a needle valve 88 at its other end. A communicating port 88 is provided between the members S1 and 58 which port comto eliminate any possibility of `-vacuum or compression which may possibly interfere with the operation of the valve 45. It is to be noted that adjustment .of the needle valve 98 will regulate the speed of the slidableplunger 5| as well as preventing said plunger from banging against the housing 58 at the termination of the strokes of said plunger. A horizontal port 55 is.provided near the upper end of said plunger while an arcuate port 55 is disposed within the lower end of the plunger. The horizontal port 43a as shown in Figure 2 is so arranged as to be connected with the pressure line 42 (Fig. 1) whereby when th`e pump 40 is exerting pressure this pressure will pass through the valve 45 by,way of the' horizontal port 55 and eventually force the vertical plunger of a pump unit upwardly. At such time as the rods have reached their maximum upward stroke, the connecting medium 45 is so arranged as to actuate the trip switch 30 to close-contacts \between said trip switch 38 and the torque motor 52 to reverse the same. Reversal of this motor will cause the gear 53 to rogear rack 54 will be lowered. Downward movement of the gear rack will change the position `ot 1g um 43 from pressure line the horizontal port 65 and arcuate port 66. This change in position of ports will prevent passage of hydraulic fluid through the connecting medi- 42 to the plunger cylinder 38. Prevention of flow of iiuid under pressure to the cylinder will effect a release of the pressure within the cylinder 38 to allow thev same to escape through the' valve 45 into return line 69 through the medium of the arcuate port 66 in cooperation with an additional connection A 61 communicating with said arcuate port whereby the weight of the sucker rods will lower the member. 32 shown in Figure 1. A horizontal port 68 disposed at right angles to the port 65 is provided whereby an exhaust is attained in the event that the use of the units B and C (Fig. 1) connected to the wells (not shown) is desired. The discharge lines 69 of the units B and C (not shown) are connected so as to communicate with this horizontal by-pass port 68 within the valve 45.

It will be understood that since the discharge A lines connected to units A; B and C are joined rods together so as to employ a common operating or master cylinder, there will be a pressure differential in the discharge from the cylinders of the units, due to differences in rod loads, sand conditions and the like. This condition may be met in any suitable manner as by varying'the diameters of cylinders employed to accord with the requirements of each individual well.

The throttle valves 44 mounted in the lines 43 are provided so that in the event the well connected to the lunit B is desired to be operated with avery slow reciprocable movement, the valve 44l may be closed to acquire the desired movement; whereas the well connected to the unit C, being entirely free of sand or like retarding substances may be actuated to its fullest operating capacity. In this event the valve 44 mounted in the unit C would be opened to its fullest extent to allow hydraulic fluidto pass therethrough from the pressure line 42 with its highest y velocity.

In Figure '1 an enlarged detail of the blow-dif l valve 10 is shown. This valve is mounted as shown in Figure 1. The purpose of this valve is to accommodate a too great an increase4 in pressure in the line 42 in the event that the valves 44 would be closed. When suii'icient pressure is built up in the line 42 to actuate the valve 10 the fluid will pass through a line 1| back into the cylinder unit A. It is to be noted especially that actuation of this relief valve 10 will close a switch 12 which switch is connected to the pump 40 and so arranged as to discontinue operation of the pump at such time as thevvalve is actuated.

In Figures 4 and 5 the universal movement between the sucker rods l2 and the unit 32 is shown. A mit 15 having its lower end rounded as at 16, is threaded on the rod l2. The member 32 is counter sunk at 11 to receive the rounded portion 16 of the nut. A slot 18 is provided in the member 32 to receive the rod l2.

In Figure 6 the plunger 31 is confined within the cylinder 38 and is actuated by pressure supplied by unit A as has hereinbeforebeen described, and a rotatable wheel is substituted for the member 32. A' cable 9| fixedly secured at one end, as shown at 92, is arranged over the wheel 90 and connected at its other end 93 to the sucker I2. It will be noted that with this arrangement of cable and wheel to the rod load that a compound ratio is had; for example: the rodline or cable 9| will move two feet to raise or 'This is I2 two feet while the actual and its attached wheel lower the sucker rod travel of the plunger 20 90 is but onefoot.

Special attention is called to the fact that, although a number of wells are operated through the medium of the master balancing unit A each well is individually controlled. Any one of a number of wells in the system may have the actuating speed thereof increased or decreased or may be completely cut off without interfering in any way with the operation of the other wells. a feature of the invention which is very important as this procedure has heretofore been unobtainable in the units now on the open market and in use.

Further when an operator desires to operate an additional number of wells it is only necessary to add additional pumping means ito the pump 40 to compensate for the additional rod load weight of the added wells. By being able to do this, the operator may at all times use the original equipment regardless of the number of wells hev desires to operate, as well as being able to operate three wells or thirty wells with the same master balancing unit. Thus a highly flexible unit is had.4

It is also to be noted that the valve 44 is provided whereby any one well may be cut out without interrupting the operation of any of the other wells in the system. This has also been impossible in the past. Also, in the mechanical units now used all wells must operate at the same speed, and the same length of stroke. The connecting mechanism hereinbefore described enables an operator to adjust the stroke as wellas the speed of the pumping mechanism of each individual well.

From the foregoing it may clearly be seen that a balanced pumping unit extremely simple in construction and economical in manufacture may be had. Not only is the installation of this unit highly economical but this unit also greatly decreases the cost of operating an oil well pumping unit. 'Ihis economy also includes the initial purchase of an oil well pumping unit. Further the automatic hydraulic balancing means serves to relieve the load imposed upon the beam actuating mechanism. Thus not only is installation but also the operating costs greatly decreased.

Manifestly, the construction as shown and described is capable of some modification and such modification as may be construed within the scope and meaning of the appended claim is also considered to be within the spirit and intent vof the invention.'

What is claimed is:

A hydraulic transmission for operating the rod string of a well pump comprising a hydraulic motor cylinder and a piston therein, a reciprocable member above and actuatedby said pispump, a motor driven main pump having itsV suction line connected to said second cylinder,

vmain pump to said motor cylinder and to connect said motor cylinder to said second cylinder, means actuated by said arm on said reciprocable Y m member for shifting said control valve from one position to the other as the motor piston reaches the end of its. respective strokes; fluid pressure means to accelerate and decelerate said motor `piston at the limit of travel in each direction.

means for regulating `the number and speedof strokes of said motor piston, and a pressure re. sponsive by-pass valve for the main pump, said -valve when open breaking the circuit `for the main pump motor. JQHN B. DAVIS. 

